A user range accuracy estimation method of the global navigation satellite system

An Analytic estimation method AEM which has less execution time is proposed to calculate the User range accuracy URA used by the user to detect the integrity potential risk. It shows that the most important thing of computing URA is to find the maximum error vector in the error vector space. By using the covariance matrix of the error vector, the searching of the maximum error vector is converted to an analytic geometry problem. The value of the maximum error vector can be obtained directly by mathematical derivation. Experiments are made to compare the performance between the proposed AEM algorithm and the Exhaustive grid search EGS method. The related results show that the AEM algorithm can reduce more than 92% of execution time. This algorithm is more suitable for computing URA at the Master control station MCS for the engineering applications.